Many image sensors used in digital cameras and other equipment having an imaging apparatus are manufactured on silicon-based substrates. Some examples of such sensors are charge-coupled device sensors (CCD) and complementary metal oxide semiconductors (CMOS). Such camera sensors have an array of photoactive (photosensitive) detectors, pixel sensors, in which each pixel may also comprise an active amplifier for amplifying the electric signal generated by the photoactive detector when it receives electromagnetic radiation (light). Usually the pixels of the image sensor are arranged in rectangular form, wherein the image sensor silicon die is a rectangle or a square.
Imaging apparatuses may also comprise one or more lenses in an optical path to provide visual information of a scene in front of the imaging apparatus on the photoactive detectors of the image sensor. If the lens or lenses have a very large wide field-of-view (180 degrees or more), they may also be called as super wide field-of-view lenses.
Lenses of imaging apparatuses may be round, wherein they draw round images on the image sensor. It may also happen that some parts of the image on the sensor are distorted.